﻿switch(navigator.userAgent){
    case "iphone":
        document.write('<meta name="viewport" content="width=device-width;user-scalable=no" />');
        break;
    default:
        var scale=Math.floor(window.screen.width/320*10)/10;
        document.write('<meta name="viewport" content="width=device-width;initial-scale=' + scale + '" />');
}